This invention relates to a stator manufacturing method in which a coil is wound on a ring-shaped core having a plurality of slots.
FIG. 10 is an overall perspective view of a coil 1 to be wound on a core of a conventional vehicular ac generator. The coil 1 is in the form of a so called starshaped coil in which a conductor is wound into a ring having a required number of turns and provided with projections and recesses corresponding to the number of poles.
FIG. 11 shows a core 3 having formed in its inner periphery a plurality of slots 2. When the coil 1 is inserted into these slots 2, a stator as illustrated in FIG. 12 is obtained.
FIGS. 13 to 16 are views illustrating the steps of inserting the coil 1 into the slots 2, in which 5 is a coil guide holder, 6 are coil guides supported by the coil guide holder 5, and 7 is a coil pusher slidable reciprocally along the coil guides 6.
In order to insert the coil 1 into the slots 2, the coil 1, which was prepared by winding an electric conductor into a ring having a necessary number of turns and formed to have radial projections and grooves corresponding to the number of poles, is mounted to the coil guides 6 (see FIG. 13). In this state, the coil 1 is lifted up by the coil pusher 7 so that the coil 1 is brought into contact with the core 3 and deformed (see FIG. 14). By further lifting up the coil pusher 7, the coil 1 is completely inserted within the slots 2 (see FIG. 15). Thereafter, the coil pusher 7 is lowered back to its original position (see FIG. 16).
According to the conventional stator manufacturing method for a vehicular a.c. generator stator, during the insertion of the coil 1 into the slots 2, the coil 1 is deformed while it is being pushed and rubbed against the core 3, the coil guides 6, coil pusher 7 and the like under an insertion pressure, so that the insulation coating of the coil 1 and the core 3 may be damaged, especially when a stator having a high space factor coil is to be manufactured.
Also, even when the coil 1 is aligned to the core 3 before insertion, it is in a misaligned state when inserted and the slot coil portion and the coil end portion are not in alignment, so that the space factor of the coil with respect to the core, the space efficiency and the cooling efficiency are disadvantageously lowered.
The stator manufacturing method of the present invention has been made to solve the above problem and has as its object the provision of a stator manufacturing method which can manufacture a stator which a high coil space factor with respect to the core, high space efficiency and high cooling efficiency.